Authorities have arrested two men in northern Mexico in connection with the shooting death of a U.S. Border Patrol agent in Arizona on Tuesday, according to news reports, although their capture remains unconfirmed by U.S. officials.

Agent Nicholas Ivie, 30, was killed and another agent wounded when they stopped to inspect a border sensor on State Highway 80, about five miles north of the Mexican border near Naco, Ariz., according to a statement from the U.S. Border Patrol. The Associated Press reports that two men were arrested in a military maneuver in Agua Prieta, Mexico; a police official in the northern Sonora state confirmed the report, the news agency said.

Calls made by TIME to U.S. Border Patrol officials and the Cochise County, Ariz. sherriffs office were not immediately returned.

Ivie, 30, a married father of two, was a four-year veteran of the agency. The second agent was released from a nearby hospital after being treated for non-life threatening injuries. A third was not hurt in the shooting.

The agents were patrolling a rugged, hilly area near the Mexican border. They had gone to inspect a tripped sensor that was installed underground to alert authorities of illegal border crossing. The area has a long history of trouble with drug smuggling operations, with porous openings in the border and adjacent areas teeming with scouts for Mexican drug cartels. Arizona Attorney General Terry Goddard has said he believes a scout was responsible for killing Douglas, Ariz., rancher Robert Krentz in 2010. His murder remains unsolved.

Two years ago, not far from where this incident took place, Agent Brian Terry was killed when he and other agents came across five men they suspected of being illegal immigrants. A firefight ensued leaving Terry dead and four of the men arrested. The weapons found at the scene were linked to the U.S Bureau of Alcohol, Tobacco and Firearms “Fast and Furious” program, which was intended to combat Mexican drug cartels and gun trafficking, but has recently come under fire in Washington because of this incident.

“This is a tragic loss for Customs and Border Protection,” said Jeffrey D. Self, commander of the Border Patrol’s Joint Field Command in Arizona in a statement, of Ivie’s death. “We have an unwavering commitment to pursue and bring the perpetrators of this heinous act to justice.”

Ivie’s family is expected to make a public statement on the killing and any subsequent investigations or arrests on Friday.